WASHINGTON (CNN) -- The Department of Homeland Security is now collecting scans of all 10 fingerprints from foreign travelers entering the United States at Dulles International Airport, and plans to extend the program to all international airports in the country by the end of next year.

The program -- known as United States Visitor and Immigration Status Indicator Technology, or US-VISIT -- had previously used only two fingerprints. The 10-print system gives the United States the ability to compare fingerprints of travelers with criminal and terrorist databases compiled by the FBI, the Defense Department and others.

The new 10-print system was rolled out in late November at Dulles.

Speaking at an event at the airport Monday, DHS Secretary Michael Chertoff touted the new technology: "We rely on biometrics, unique physical characteristics like fingerprints, to keep dangerous people out of the United States and at the same time to keep the lines moving so that travel is fast and convenient for legitimate citizens and visitors."

Chertoff said the two-fingerprint version of the program, which began in 2004, has already been successful, claiming that the program had stopped "almost 2,000 criminals and immigrant violators based on their fingerprints alone."

Canadians and Mexicans using government-issued identification cards are exempt from the program.

Privacy advocates such as the Electronic Privacy Information Center claim the system puts personal information at risk. A July 2007 Government Accountability Office report found that "systems supporting the US-VISIT program have significant information security control weaknesses that place sensitive and personally identifiable information at increased risk of unauthorized and possibly undetected disclosure and modification, misuse and destruction."

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DHS insists that there have been no privacy breaches in the US-VISIT program.

Chertoff played down risks. "Moving to 10 fingerprints is completely consistent with, and in fact enhances, our ability to protect," he said. "We view privacy as a fundamental human right and preserving it is an integral part of our mission."

Travel and tourism groups fear that more barriers to international travel will make foreigners less likely to visit the United States. Discover America Partnership, a trade group representing the tourism industry, is cautiously supporting the program, but urges a greater effort by the United States to make foreign travelers aware of the program.

"While reasonable, we must also recognize that the 10-finger scan technology may be perceived as a barrier to entry," said Geoff Freeman, executive director of Discover America Partnership, in a news release. "We must balance this and other barriers with clear communications and a welcoming message." E-mail to a friend